This invention relates to hydrocyclones.
A hydrocyclone is a device that receives a slurry of liquid and solids and separates liquid from the solids. The hydrocyclone has a feed section which has a horizontal inlet to introduce the slurry tangentially under pressure and has an upper opening to discharge water. The hydrocyclone has a lower separating section which includes a conical chamber that terminates in an outlet through which the solids and some entraining water are discharged.
The tangentially-introduced slurry creates a vortex in the center of the feed section with centrifugal force driving the solids radially outwardly. A tube depending slightly from the tangential feed opening is a vortex finder through which water, largely separated from the solids, rises and flows out the upper section. The solids are forced downwardly through an outlet in the lower conical chamber.
The hydrocyclone manufactured by the assignee, Eagle-Picher Industries, Inc., has a urethane valve and valve holder in the outlet in the lower section. The valve has a cylindrical opening and by rotating the valve holder the diameter of the cylindrical opening can be varied. When the valve is squeezed down, the percentage of solids flowing through the outlet increases until a "rope flow" is created, the rope flow being a sausage-like stream of solids with the solids being more than fifty percent by weight of the effluent. While squeezing down the outlet through the valve is effective in reducing the water content of the effluent, there is a trade off, namely, that the hydrocyclone plugs or the efficiency goes way down.